T he Hubble telescope (pictured right) was named after the great American visionary, Edwin Hubble, the man who discovered galaxies beyond the Milky Way, the astronomer who spotted that the universe was expanding. But the telescope itself began life with blurred vision.

It was designed to get above the atmospheric murk that makes stars twinkle and cast a cold, all-seeing eye on the distant heavens. It was completed in 1985, and finally went into orbit in 1990 - and only then did scientists discover that something had gone horribly wrong.

Its giant mirror was out of true: too flat on one edge by just one-50th of the thickness of a human hair, but enough to ruin the big picture. A US senator condemned the project as a techno-turkey. Within three years, Nasa astronauts aboard a space shuttle had fitted a specially tailored camera to correct the case of myopia 360 miles above the planet - and then the fun began. The data beamed down to Baltimore began to astonish the world.

Each wide-screen image was a kind of all-star production set in the great universal studios, and each told a story of the galaxy far away and long ago. A telescope is a time machine: the light that hits its mirror left its source a million or a billion years ago. Hubble began to capture moments in the life and death of ancient stars. It peered into the Lagoon Nebula 5,000 light years away in Sagittarius, to see the celestial equivalent of tornadoes - twisters, eerie funnels and ropes half a light year long, driven by violent stellar winds slamming into cool clouds of gas and dust from which stars are born.

It looked into a tiny speck of deep dark space in the constellation Orion - and it kept staring at the same point on every orbit. Each time, its cameras recorded photons of light too faint for any other instrument. At the end of a million seconds of observation, Hubble had done something once beyond belief: it had collected the gleam of 10,000 galaxies that glowed in the very early universe more than 10bn years ago, "within a stone's throw of the big bang itself," said a triumphant astronomer.

It used false colour to highlight the spectrum of radiation from faraway objects, and by accident made glorious art from a scientific study of the gas and dust around Eta Carinae, a star 8,000 light years away, and 100 times more massive than the sun. It homed in on the spiral arms of the Whirlpool Galaxy, to pinpoint the birth of huge stars, gleaming like diamonds on a dusty rope. In 1997, astronauts visited the space telescope to extend its life.

On Monday, the US space agency looked at its budget for 2006 and decided that - with a half-built space station, a tragically reduced shuttle fleet, and a promise to return to the moon - it could no longer promise a future for the instrument that delighted a generation. But Hubble's scientific fan club will not give up easily. They want a new space telescope, or the old one to continue. The politics will go on. Watch, as astronomers say, this space.